Self-aggregated nanoparticles from linoleic acid modified carboxymethyl chitosan: Synthesis, characterization and application in vitro

Recent advances on formation mechanism and functionality of chitosan-based conjugates and their application in o/w emulsion systems: A review

Chitosan is very attractive in the food industry due to its good biocompatibility and high biodegradability. In particular, it can be used as a preferred material for the fabrication of stabilizers in emulsion-based foods. However, poor solubility and antioxidant activity limit its wide application. The functionality of chitosan can be extended by forming chitosan-based conjugates, which can be used to modulate the characteristics of the oil-water interface, thereby improving the stability and performance of the o/w emulsions. This review highlights the recent progress of chitosan-based conjugates, focusing on the classification, formation mechanism and functional properties, and the applications of these conjugates in o/w emulsions are summarized. Lastly, the promising research trends and challenges of chitosan-based conjugates and their emulsion systems in this field are also discussed. This review will provide a theoretical basis for the wide application of chitosan-based conjugates in emulsion systems.

Review of Contemporary Self-Assembled Systems for the Controlled Delivery of Therapeutics in Medicine

The novel and unique design of self-assembled micro and nanostructures can be tailored and controlled through the deep understanding of the self-assembly behavior of amphiphilic molecules. The most commonly known amphiphilic molecules are surfactants, phospholipids, and block copolymers. These molecules present a dual attraction in aqueous solutions that lead to the formation of structures like micelles, hydrogels, and liposomes. These structures can respond to external stimuli and can be further modified making them ideal for specific, targeted medical needs and localized drug delivery treatments. Biodegradability, biocompatibility, drug protection, drug bioavailability, and improved patient compliance are among the most important benefits of these self-assembled structures for drug delivery purposes. Furthermore, there are numerous FDA-approved biomaterials with self-assembling properties that can help shorten the approval pathway of efficient platforms, allowing them to reach the therapeutic market faster. This review focuses on providing a thorough description of the current use of self-assembled micelles, hydrogels, and vesicles (polymersomes/liposomes) for the extended and controlled release of therapeutics, with relevant medical applications. FDA-approved polymers, as well as clinically and commercially available nanoplatforms, are described throughout the paper.

Docetaxel-Loaded Chitosan-Cholesterol Conjugate-Based Self-Assembled Nanoparticles for Overcoming Multidrug Resistance in Cancer Cells

Cholesteryl hemisuccinate (CHS)-conjugated chitosan (CS)-based self-assembled nanoparticles (NPs) were developed for enhancing the intracellular uptake of docetaxel in multidrug resistance (MDR)-acquired cancer cells. CHS-CS was successfully synthesized and self-aggregation, particle size, zeta potential, drug entrapment efficiency, and in vitro drug release of docetaxel-loaded CHS-CS NPs were tested. The optimized NPs had a mean hydrodynamic diameter of 303 nm, positive zeta potential of 21.3 mV, and spherical shape. The in vitro release of docetaxel from the optimized CHS-CS NPs in different pH medium (pH 6.0 and 7.4) revealed that the release was improved in a more acidic condition (pH 6.0), representing a tumor cell's environment. The superior MDR-overcoming effect of docetaxel-loaded CHS-CS NPs, compared with docetaxel solution, was verified in anti-proliferation and cellular accumulation studies in MDR-acquired KBV20C cells. Thus, CHS-CS NPs could be potentially used for overcoming the MDR effect in anticancer drug delivery.

Polymeric micelles based on amphiphilic oleic acid modified carboxymethyl chitosan for oral drug delivery of bcs class iv compound: Intestinal permeability and pharmacokinetic evaluation

Chemical modification of chitosan derivatives with hydrophobic fatty acids to enhance their self-aggregation behavior is well established. Previously our group reported low molecular weight carboxymethyl chitosan (CMCS) which showed enhancement in apparent permeability of hydrophobic drug, tamoxifen. Further extension to this work, herein we synthesize a new polymer of oleic acid grafted low molecular weight carboxymethyl chitosan (OA-CMCS) for maneuvering biopharmaceutical performance of poorly water soluble drugs. This polymer was designed and synthesized via amidation reaction and well characterized by analytical tools like 1H-NMR and FT-IR spectroscopy. OA-CMCS conjugate easily self-organized into micelles like structure in an aqueous medium and showed a low critical micellar concentration of 1 µg/mL. Poorly water-soluble drug, docetaxel (DTX) was used as a model drug in this study. Optimization of variables resulted in the formation of spherical DTX loaded OA-CMCS micelles in the size range of 213.4 ± 9.6 nm with an entrapment efficiency of 57.26 ± 1.25%. DTX loaded OA-CMCS micelles showed slow and sustained DTX release behavior in simulated body fluid during in vitro release study. The permeability of DTX loaded OA-CMCS micelles across the gastrointestinal tract were investigated by in vitro Caco-2 cells model. The apparent permeability of DTX loaded OA-CMCS micelles improved up to 6.57-fold in comparison to free DTX suspension which indicates the increase in paracellular absorption of DTX. Additionally, in vivo pharmacokinetic study demonstrates an increase in Cmax (1.97-fold) and AUC (2.62-fold) for DTX loaded OA-CMCS micelles compared to free DTX suspension. Hence, we propose OA-CMCS as a promising cargo to incorporate drugs for enhancement of biopharmaceutical performance.

Biofabrication of Chitosan-Based Nanomedicines and Its Potential Use for Translational Ophthalmic Applications

Drug delivery to the anterior and posterior segment of eye remains a challenge. Nanoparticle-mediated drug delivery has indicated some promise. The presented review aims to summarize recent advancements in chitosan-based nanotherapies for ocular drug delivery and the challenges encountered during the process. Significant research using chitosan, a cationic linear polymer, is being conducted for ocular drug delivery. A vast number of publications exploit the mucoadhesive properties of the polymer, which arise due to interactions between the amino acids of chitosan and the sialic acid residues in mucous. The high degree of crosslinking in chitosan nanoparticles facilitates a dramatic increase in ocular drug retention of the desired drug, which subsequently helps in ocular penetration and improving the bioavailability of the drugs. A noted decrease in the initial burst of the drug is the basis for developing sustained drug release formulation using biodegradable and biocompatible chitosan polymer. In vitro as well as in vivo studies have indicated enhancement in the uptake, accumulation, and removal of chitosan nanoparticles from the site of delivery. In summary, chitosan- or modified-chitosan-based nanoparticles are being widely tested as drug carriers for treatment of bacterial and viral infections, glaucoma, age-related macular degeneration, and diabetic retinopathy.

Study of injectable Blueberry anthocyanins-loaded hydrogel for promoting full-thickness wound healing

Injectable hydrogels with high anti-inflammatory and wound-healing properties are highly desirable for clinical application. In the present study, injectable hydrogels were prepared based on carboxymethyl chitosan and oxidized hyaluronic acid. Blueberry anthocyanins (BA), which are known for their antioxidant and antiinflammatory properties, were successfully loaded into the hydrogels. The gelation kinetics and mechanical properties of the hydrogels were investigated. Oxidized hyaluronic acid with an oxidation degree of 38.1% conferred a suitable gelation time (~70 s) and mechanical properties (76.0 kPa compression stress at strain of 80%) of the hydrogel. The injectable BA-loaded hydrogel significantly accelerated the wound healing process in a full-thickness skin wound model in rats, promoted epithelial and tissue regeneration, exerted antiinflammatory effects, and promoted collagen deposition and angiogenesis. Besides, the hydrogel could upregulate the expression of VEGF and IL-10 proteins, downregulate the NF-κB level, and promote macrophage transformation from M1 phenotype to M2. The promotion of the BA-loaded hydrogel on wound healing were mainly realized by its biological effects, including antioxidant and anti-inflammatory effects, and regulation of various wound healing related factors. The results suggested that BA and the hydrogels exert synergistic effects in promoting wound healing. Injectable BA-loaded hydrogels appear to be promising candidates for wound healing application.

Characterization and evaluation of a novel O-carboxymethyl chitosan films with Mimosa tenuiflora extract for skin regeneration and wound healing

In this study, films of O-carboxymethyl chitosan with Mimosa tenuiflora extract were manufactured, characterized, and evaluated. In this work, both the synthesis of O-carboxymethyl chitosan and the extraction of the active ingredient of Mimosa tenuiflora extract from the cortex are described. First, the extract of Mimosa tenuiflora in water was obtained by precipitation with ethanol, filtering, and concentrating. Subsequently, a study was conducted of scratch wound healing to determine the optimal concentration of extract to be used in the manufacture of films. The produced O-carboxymethyl chitosan films and the Mimosa tenuiflora extract were mixed, and their chemical composition, tensile properties, and wettability were characterized by Fourier-transform infrared spectroscopy, mechanical tests, and contact angle measurement. The antimicrobial properties of the films were tested by turbidimetry using two types of bacteria. In addition, a study of the enzymatic degradation of the films with the enzyme lysozyme was performed. Finally, in vitro studies to assess the biocompatibility and cytotoxicity of films with fibroblastic cells were carried out as well as the kinetic analysis of healing in mice. It was found that the addition of Mimosa tenuiflora extract in the polymer matrix of the films made with O-carboxymethyl chitosan improves the proliferation of fibroblast and accelerates wound healing, thus providing a novel biomaterial for skin regeneration.

Hydrophobically Modified Glucan as an Amphiphilic Carbohydrate Polymer for Micellar Delivery of Myricetin

Myricetin (Myr) is a phytochemical with many functional properties. However, its hydrophobicity, low bioavailability, and stability limit its application. In this study, octadecanoate oat β-glucan (OGE) was synthesized and gained recognition as a self-assembled micelle forming a polymer with a critical micelle concentration (CMC) of 59.4 μg/mL. The Myr-loaded OGE micelle was then prepared and characterized by dynamic light scattering (DLS), transmission electron microscope (TEM), X-ray diffractometer (XRD), and Fourier-transform infrared spectroscopy (FT-IR) spectra. The water solubility of Myr was greatly enhanced by forming the Myr/OGE inclusion complex. Consequently, compared to free Myr, the retention of Myr in Myr-loaded OGE micelle was effectively increased during the intestinal digestion phase, and its antioxidant activity was also improved. Overall, our findings demonstrated the potential applications of OGE polymer for the development of prospective micelle in health food, cosmetics, and pharmaceutical fields because they can aid in the delivery of hydrophobic functional compounds like Myr.

Advances in chitosan-based nanoparticles for oncotherapy

Chitosan has attracted considerable attention as an anti-tumor drug carrier material in recent years, which is due to its biocompatibility and biodegradability, as well as the simple and mild preparing techniques of drug-loaded nanoparticles. Chitosan-based nanoparticles can deliver various anti-tumor agents to specific tumor tissues by passive and active targeting mechanisms, including traditional chemotherapeutic agents, DNA or siRNA, proteins, photosensitizers and so on. In this review, we summarized the factors affecting the anti-tumor efficacy of chitosan-based nanoparticles, to aid exploring the function-structure relationship. The recent studies on chitosan-based nanoparticles for oncotherapy were highlighted, including their structures, properties and pharmacological effects. Finally, we offered our perspectives on the challenges and future development of this area.

Chitosan-based nanoparticles as drug delivery systems: a review on two decades of research

Chitosan (CS) is one of the most functional natural biopolymer widely used in the pharmaceutical field due to its biocompatibility and biodegradability. These privileges lead to its application in the synthesis of nanoparticles for the drug during the last two decades. This article gives rise to a general review of the different chitosan nanoparticles (CSNPs) preparation techniques: Ionic gelation, emulsion cross-linking, spray-drying, emulsion-droplet coalescence method, nanoprecipitation, reverse micellar method, desolvation method, modified ionic gelation with radial polymerisation and emulsion solvent diffusion, from the point of view of the methodological and mechanistic aspects involved. The physicochemical behaviour of CSNPs including drug loading, drug release, particles size, zeta potential and stability are briefly discussed. This review also directs to bring an outline of the major applications of CSNPs in drug delivery according to drug and route of administration. Finally, derivatives of CSNPs and CS nano-complexes are also discussed.

Evaluation of the PEG Density in the PEGylated Chitosan Nanoparticles as a Drug Carrier for Curcumin and Mitoxantrone

Polyethylene glycolated (PEGylated)curcumin-grafted-chitosan (PCC) conjugates were synthesized with three PEG/chitosan feed molar ratios (1/5, 1/7.5, and 1/10), namely PCC1, PCC2 and PCC3. Chemical structures of these conjugates were characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (¹H NMR). The degrees of substitution (DS) of PEG were 0.75%, 0.45% and 0.33%, respectively, for PCC1, PCC2 and PCC3by ¹H NMR analysis. Self-assembled PCC nanoparticles (NPs) were spherical as observed in transmission electron microscope images. Mitoxantrone (MTO)-loaded PCC NPs were prepared to analyze the particle size, zeta potential, drug loading, drug release and in vitro cytotoxicity. The MTO-loaded PCC3 NP (DS = 0.33%) possessed the smallest size (~183.1 nm), highest zeta potential (~+34.0 mV) and the largest loading capacity of curcumin (CUR, ~16.1%) and MTO (~8.30%). The release results showed that MTO-loaded PCC3 NP demonstrated the lowest percentage of MTO release and increased as pH decreased, but the CUR release could only be detected at pH 4.0. In the cytotoxicity study, MTO-loaded PCC3 NP displayed the highest cytotoxicity in HepG2 cell line and the best synergistic effect among the tested NPs. Our results suggest that the DS of PEG has impacts on the structures and functions of PCC NPs: the smaller DS of PEG was associated with the smaller size, the higher zeta potential, the slower drug release, and the higher cytotoxicity of NPs.

Carboxymethyl Chitosan and Its Hydrophobically Modified Derivative as pH-Switchable Emulsifiers

The emulsification properties of carboxymethyl chitosan (CMChi) and hydrophobically modified carboxymethyl chitosan (h-CMChi) were studied as a function of pH and dodecane/water ratio. The pH was varied between 6-10, and the oil/water ratio between 0.1-2.0. In CMChi solution, the emulsion stability increased as the pH was lowered from 10 to 7, and the phase inversion was shifted from oil/water ratio 1.0 to 1.8, respectively. The system behaved differently in pH 6 due to the aggregation of CMChi and the formation of nanoparticles (∼200-300 nm). No phase inversion was observed and the maximum amount of emulsified oil was reached at oil/water ratio 1.2. The h-CMChi showed similar behavior as a function of pH but, due to hydrophobic modification, the phase inversion was shifted to higher values in pH 7-10. In pH 6, the behavior was similar, but the maximum amount of emulsified oil was higher compared to CMChi. The amount of adsorbed particles correlated with the emulsified amount of oil. Reversible emulsification of dodecane was demonstrated by pH adjustment using CMChi and h-CMChi solutions. The formed emulsions were gel-like, suggesting particle-particle interaction.

Synthesis and evaluation of pH-sensitive, self-assembled chitosan-based nanoparticles as efficient doxorubicin carriers

A novel pH-responsive polymer based on amphiphilic N-acetyl histidine and arginine-grafted chitosan was synthesized using N-acetyl histidine as hydrophobic segment and arginine as hydrophilic segment by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-mediated coupling reactions as anticancer drug delivery system for doxorubicin. The structure of the synthesized polymer was confirmed by Fourier transform infrared and ¹H nuclear magnetic resonance analysis. Due to self-association behavior, N-acetyl histidine and arginine-grafted chitosan structured nanoparticles with in size range of 204 nm. N-acetyl histidine and arginine-grafted chitosan with different substitution degree of N-acetyl histidine were initially prepared and characterized. The critical micelle concentration decreased with increasing substitution degree of N-acetyl histidine. Furthermore, N-acetyl histidine and arginine-grafted chitosan nanoparticles exhibited an acidic pH-triggered aggregation and disassembling nature. The doxorubicin-encapsulated nanoparticles based on synthesized conjugate ( N-acetyl histidine and arginine-grafted chitosan/doxorubicin nanoparticles) showed a sustained drug release pattern, which could be hastened under acidic pH conditions but delayed with increasing substitution degree of N-acetyl histidine. Anticancer effects demonstrated that N-acetyl histidine and arginine-grafted chitosan/doxorubicin nanoparticles could suppress both sensitive and resistant human breast tumor cell line (MCF-7) efficiently in a dose- and time-dependent pattern. Confocal microscopy results evidenced increased cellular uptake and enhanced retention of the synthesized nanoparticles in drug-resistant cells demonstrating better efficacy of nanoparticles over native doxorubicin. These results suggest that N-acetyl histidine and arginine-grafted chitosan/doxorubicin nanoparticles might be promising carriers for delivery of hydrophobic drug doxorubicin against drug-resistant tumors.

Carbohydrate-based amphiphilic nano delivery systems for cancer therapy

Nanoparticles (NPs) are novel drug delivery systems that have been attracting more and more attention in recent years, and have been used for the treatment of cancer, infection, inflammation and other diseases. Among the numerous classes of materials employed for constructing NPs, organic polymers are outstanding due to the flexibility of design and synthesis and the ease of modification and functionalization. In particular, NP based amphiphilic polymers make a great contribution to the delivery of poorly-water soluble drugs. For example, natural, biocompatible and biodegradable products like polysaccharides are widely used as building blocks for the preparation of such drug delivery vehicles. This review will detail carbohydrate based amphiphilic polymeric systems for cancer therapy. Specifically, it focuses on the nature of the polymer employed for the preparation of targeted nanocarriers, the synthetic methods, as well as strategies for the application and evaluation of biological activity. Applications of the amphiphilic polymer systems include drug delivery, gene delivery, photosensitizer delivery, diagnostic imaging and specific ligand-assisted cellular uptake. As a result, a thorough understanding of the relationship between chemical structure and biological properties facilitate the optimal design and rational clinical application of the resulting carbohydrate based nano delivery systems for cancer therapy.

Designing polymers with sugar-based advantages for bioactive delivery applications

Sugar-based polymers have been extensively explored as a means to increase drug delivery systems' biocompatibility and biodegradation. Here,we review he use of sugar-based polymers for drug delivery applications, with a particular focus on the utility of the sugar component(s) to provide benefits for drug targeting and stimuli responsive systems. Specifically, numerous synthetic methods have been developed to reliably modify naturally-occurring polysaccharides, conjugate sugar moieties to synthetic polymer scaffolds to generate glycopolymers, and utilize sugars as a multifunctional building block to develop sugar-linked polymers. The design of sugar-based polymer systems has tremendous implications on both the physiological and biological properties imparted by the saccharide units and are unique from synthetic polymers. These features include the ability of glycopolymers to preferentially target various cell types and tissues through receptor interactions, exhibit bioadhesion for prolonged residence time, and be rapidly recognized and internalized by cancer cells. Also discussed are the distinct stimuli-sensitive properties of saccharide-modified polymers to mediate drug release under desired conditions. Saccharide-based systems with inherent pH- and temperature-sensitive properties, as well as enzyme-cleavable polysaccharides for targeted bioactive delivery, are covered. Overall, this work emphasizes inherent benefits of sugar-containing polymer systems for bioactive delivery.

Advances in self-assembled chitosan nanomaterials for drug delivery

Nanomaterials based on chitosan have emerged as promising carriers of therapeutic agents for drug delivery due to good biocompatibility, biodegradability, and low toxicity. Chitosan originated nanocarriers have been prepared by mini-emulsion, chemical or ionic gelation, coacervation/precipitation, and spray-drying methods. As alternatives to these traditional fabrication methods, self-assembled chitosan nanomaterials show significant advantages and have received growing scientific attention in recent years. Self-assembly is a spontaneous process by which organized structures with particular functions and properties could be obtained without additional complicated processing or modification steps. In this review, we focus on recent progress in the design, fabrication and physicochemical aspects of chitosan-based self-assembled nanomaterials. Their applications in drug delivery of different therapeutic agents are also discussed in details.

pH-sensitive chitosan-derived nanoparticles as doxorubicin carriers for effective anti-tumor activity: preparation and in vitro evaluation

pH-sensitive self-aggregated nanoparticles (SNPs), based on amphiphilic deoxycholic acid (DOCA) modified carboxymethyl chitosan (DCMC), were prepared for delivery of the anticancer drug doxorubicin (DOX). DCMCs with different degrees of substitution (DS) of DOCA were initially synthesized and characterized. Based on self-aggregation, DCMC formed nanoparticles with size ranging from 87 to 174 nm. The critical aggregation concentration (CAC) decreased on increasing the DS of DOCA. Moreover, the DCMC SNPs showed an acidic pH-induced aggregation and deformation behavior. The DOX-loaded SNPs ([D]NP) exhibited a sustained drug release manner, which could be accelerated by an acidic pH, but delayed by a higher DS of DOCA. Antitumor efficacy results showed that [D]NP could suppress both sensitive and resistant MCF-7 cells effectively in a dose- and time-dependent manner. The enhanced cellular uptake and greater retention of [D]NP in drug-resistant cells, as evidenced by confocal microscopy and flow cytometry, contributed to a superior efficacy of [D]NP over free DOX. These results suggest the potential of DCMC SNPs as carriers for the hydrophobic drug DOX for effective cancer therapy against drug-resistant tumors.

Preparation and characterization of self-assembled nanoparticles based on folic acid modified carboxymethyl chitosan

Folate (FA) modified carboxymethyl chitosan (FCC) has been synthesized and the hydrogel nanoparticles can be prepared after the sonication. Formation and characteristics of nanoparticles of FCC were studied by fluorescence spectroscopy and dynamic light scattering methods. The critical aggregation concentration value of FCC in water was 9.34 × 10(-2) mg/ml and the mean hydrodynamic diameter of particle was 267.8 nm. The morphology of nanoparticles was observed by transmission electron microscopy which had spherical shape. Loading capacity (LC), loading efficiency (LE) and the in vitro release profiles of nanoparticles were investigated by doxorubicin (DOX) as a model drug. When the initially added amount of DOX versus the constant amount of FCC polymer was increased, the LC in the nanoparticles was gradually increased and the LE decreased. The in vitro release profile of the DOX from the FCC nanoparticles exhibited sustained release. Cellular uptake of FCC nanoparticles was found to be higher than that of nanoparticles based on linoleic acid (LA) modified carboxymethyl chitosan because of the FA-receptor-mediated endocytosis, thereby providing higher cytotoxicity against Hela cells.

Preparation and characterization of nanoparticles based on hydrophobic alginate derivative as carriers for sustained release of vitamin D3

Hydrophobic alginate derivative was prepared by modification of alginate by acid chloride reaction using oleoyl chloride without organic solvents. The conjugate of oleoyl alginate ester (OAE) was confirmed by FT-IR and (1)H NMR. The degree of substitution (DS) of OAE was determined by (1)H NMR, and it ranged from 0.84 to 3.85. In distilled water, OAE formed self-assembled nanoparticles at low concentrations in aqueous medium, and nanoparticles retained their structural integrity both in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The loading and release characteristics of nanoparticles based on OAE were investigated using vitamin D(3) as a model nutraceutical. As the concentration of vitamin D(3) increased, the loading capacity (LC) increased, whereas the loading efficiency (LE) decreased. Nanoparticles could release vitamin D(3) at a sustained rate in gastrointestinal fluid. These results revealed the potential of OAE nanoparticles as oral carriers for sustained release of vitamin D(3).

Synthesis, characterization and cytotoxicity studies of chitosan-coated tea polyphenols nanoparticles

Chitosan nanoparticles (CS-NPs) were prepared by ionic gelation method using carboxymethyl chitosan and chitosan hydrochloride as carriers of tea polyphenols. The characteristics of chitosan-coated tea polyphenols nanoparticles (CS-TP NPs) were determined by using transmission electron microscopy (TEM) and FT-IR spectroscopy. It was found that the synthesized CS-TP NPs were non-spherical in shape with an average size of 407±50nm. Meanwhile, the drug content and encapsulation rate of the nanoparticles was 8-16% and 44-83%, respectively. These CS-TP NPs also demonstrated sustained release of tea polyphenols in PBS. The antitumor of CS-TP NPs towards HepG2 cancer cells was investigated. The result showed that CS-TP NPs retained significant antitumor activities.

Self-Assembled Hydrogel Nanoparticles for Drug Delivery Applications

Hydrogel nanoparticles—also referred to as polymeric nanogels or macromolecular micelles—are emerging as promising drug carriers for therapeutic applications. These nanostructures hold versatility and properties suitable for the delivery of bioactive molecules, namely of biopharmaceuticals. This article reviews the latest developments in the use of self-assembled polymeric nanogels for drug delivery applications, including small molecular weight drugs, proteins, peptides, oligosaccharides, vaccines and nucleic acids. The materials and techniques used in the development of self-assembling nanogels are also described.

Targeted delivery of low molecular drugs using chitosan and its derivatives

Chitosan has prompted the continuous impetus for the development of safe and effective drug delivery systems because of its unique physicochemical and biological characteristics. The primary hydroxyl and amine groups located on the backbone of chitosan allow for chemical modification to control its physical properties. When the hydrophobic moiety is conjugated to a chitosan molecule, the resulting amphiphile may form self-assembled nanoparticles that can encapsulate a quantity of drugs and deliver them to a specific site of action. Chemical attachment of the drug to the chitosan throughout the functional linker may produce useful prodrugs, exhibiting the appropriate biological activity at the target site. Mucoadhesive and absorption enhancement properties of chitosan increase the in vivo residence time of the dosage form in the gastrointestinal tract and improve the bioavailability of various drugs. The main objective of this review is to provide an insight into various target-specific carriers, based on chitosan and its derivatives, towards low molecular weight drug delivery. The first part of the review is concerned with the organ-specific delivery of low molecular drugs using chitosan and its derivatives. The subsequent section considers the recent developments of drug delivery carriers for cancer therapy with special focus on various targeting strategies.